Role of corticosterone on the development of passive electrical properties of cultured chick embryo neurons.
We worked with neuronal cells of chick embryo cultures. The cells were obtained from 7 days-old embryos and cultured for 12 days. The experimental group was submitted to a single dose of corticosterone during the first 48 hours of culture. We measured the membrane resting potential at different external potassium concentrations, as well as the passive electrical properties of the membrane, resistance, time constant and capacitance. We found that the control cells develop progressively their potassium permeability and the electrical properties of the membrane until reaching values in this parameters that were similar to those found in adult cells. Corticosterone application induced a significant enhancement in these parameters in 3 and 6 days-old cultures as compared with the control cultures. These results suggest that glucocorticoids accelerate the differentiation process of the neurons in culture when applied at very early stages of development. We discuss the possible mechanisms involved in this action.
Fuentes-Pardo
B
B
Depto. de Fisiología, Facultad de Medicina, UNAM, D.F. México.
Hernández-Falcön
J
J
Velázquez
P N
PN
Romano
M C
MC
D000818:Animals; D002463:Cell Membrane Permeability / Q000187:drug effects / Q000502:physiology; D002478:Cells, Cultured; D002642:Chick Embryo; D003345:Corticosterone / Q000032:analysis / Q000502:physiology*; D003470:Culture Media / Q000737:chemistry / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D004553:Electric Conductivity / Q000187:drug effects / Q000502:physiology*; D008564:Membrane Potentials / Q000187:drug effects / Q000502:physiology*; D009474:Neurons / Q000187:drug effects / Q000502:physiology*; D011188:Potassium / Q000493:pharmacokinetics
D003470:Culture Media; D011188:Potassium; D003345:Corticosterone